The present invention is directed to methods and apparatus for dispersing material, particularly granular chemical material. The invention is particularly adapted for dispensing agricultural treatment material, such as pesticides, herbicides, fungicides, and fertilizer from an apparatus driven over the terrain onto which the treatment materials are to be applied.
Agricultural dispensing apparatus, more commonly known as granular spreaders, generally include a wheeled vehicle, either self-powered (e.g., motorized) or manually driven, including a housing having a hopper for receiving a container holding the product to be dispersed, and metering means for controlling the quantity of material flowing from the product container, by gravity feed, and onto dispersing means, such as a rotating plate, positioned beneath the metering means for receiving material deposited thereon. The apparatus is driven along terrain to be treated, and the material to be applied to the terrain is dispersed from the moving apparatus by the rotational forces applied by the rotating plate.
Known agricultural spreaders exhibit disadvantages which include: variations in the rotational speed of the dispersing plate (and thereby variations in the distance which material is propelled from the spreader) in proportion to changes in the linear speed of the spreader; imprecise metering of material deposited on the disperser plate from the product container during repeated dispersing operations; the inability to control the angular orientation at which material is dispersed from the spreader; and the inability to automatically disengage the metering means from the disperser plate to prevent material from being deposited on the disperser plate when the spreader is moved in a reverse direction.
It is the primary object of the present invention to provide an improved spreader, particularly for dispensing granular agricultural materials onto terrain over which the spreader is driven, which overcomes the aforementioned disadvantages, and others, encountered in the operation of known dispersing apparatus. Other objects and advantages of the methods and apparatus in accordance with the present invention will become apparent from the following description of the invention in conjunction with the drawings.